Answer: a) Theory
Explanation: “Dalton’s Atomic Theory”
b) When iron rusts in a container... is an Observation
c) The “Law”of Conservation of Mass
d) is an observation
Answer:
a) 40 V
b) 69.23 V
c) 69.23 V
Explanation:
See attachment for solution
Angular velocity means how many radians/degrees is this hand passing by every second.
First, you realize it goes through a whole revolution (2

in radians) in 60 seconds.
This means for every second, it passes by:

For the next part, you need to know this equation:
Tangential velocity=Angular velocity x radius (meters)

The answer for this question, If I am correct, should be answer "D".
Answer: lodestone
An example of a natural magnet is the lodestone, also called magnetite. Other examples are pyrrhotite, ferrite, and columbite.
Classification of Magnets
Lodestones are a common example of natural magnets. Artificial magnets – Artificial magnets can be produced by man-made means and have a stronger magnetic field. They can also be shaped as required. When an artificial magnet is shaped in the form of a bar, it is called a bar magnet.
Explanation: